Problem running the discoverydemo

Hi all!
    I am a new user of JXTA. An I am following the programming guide.
When I tried to run the DiscoveryDemo, I couldn't receive any Discovery
Responses and at the same time errors accured. I have checked the JXTA
configurator, but I have no idea about what should I add to rendezvous
seed peers and relay seed peers. My computer is using the VPN of our
school to connect with the internet, how should I configure the firewall
or proxy? I couldn't find the item to configure the proxy here. The
error information is as follows:

- New TCP Connection to : tcp://209.128.126.120:9711 /
209.128.126.120:9711
- New TCP Connection to : tcp://209.128.126.123:9701 /
209.128.126.123:9701
- New TCP Connection to : tcp://192.18.37.37:9701 / 192.18.37.37:9701
- Could not make messenger for http://192.18.37.37:9700
java.lang.NoSuchFieldError: TRACE
	at
net.jxta.impl.endpoint.servlethttp.HttpClientMessenger.retreiveLogicalDe
stinationAddress(HttpClientMessenger.java:401)
	at
net.jxta.impl.endpoint.servlethttp.HttpClientMessenger.<init>(HttpClient
Messenger.java:209)
	at
net.jxta.impl.endpoint.servlethttp.HttpMessageSender.getMessenger(HttpMe
ssageSender.java:206)
	at
net.jxta.impl.endpoint.EndpointServiceImpl.getLocalTransportMessenger(En
dpointServiceImpl.java:1530)
	at
net.jxta.impl.endpoint.EndpointServiceImpl$CanonicalMessenger.connectImp
l(EndpointServiceImpl.java:379)
	at
net.jxta.endpoint.ThreadedMessenger.connect(ThreadedMessenger.java:520)
	at
net.jxta.endpoint.ThreadedMessenger.run(ThreadedMessenger.java:361)
	at java.lang.Thread.run(Thread.java:595)
- Ping (http://209.128.126.123:9710/) -> failed
- Failed to connect to http://209.128.126.123:9710 : Connection refused:
connect
Thank you so much!

Ouyang Yang
Research Fellow 
School of Information Systems
Singapore Management University
[email protected]